References
PMID:11149925
2 classes of negative regulators of Rho proteins have been described. GAPs and GDIs.
Rho proteins have relatively slow intrinsic rates of GTP hydrolysis that can be accelerated by GAPs (GTPase activating proteins).
Another class of proteins shown to inhibit the release of GDP from Rho proteins, GDIs (GDP Dissociation Inhibitors (GDIs) have been described.
Perhaps more important than their effects on the GDP/GTP cycle is the ability of GDIs to solubilize membrane-associated Rho proteins.
RhoA is sequestered in the cytosol by a RhoGDI-dependent and -independent mechanisms.
RhoGDI binding is not affected by the length of the prenyl chain (farnesylation versus geranylgeranylation)
Palmitoylation blocks RhoGDI binding.
PMID:9113980
GDIs play a primary role in modulating the activation of GTPases and may also be critical for the cellular compartmentalization of GTPases.